The **M2AS1-4133-R2/N** is a specific networking/telecommunications component, typically identified as a **QSFP28 to 4x SFP28 Passive Copper Breakout Cable** (often associated with brands like Mellanox/NVIDIA or compatible third-party manufacturers). Below is the technical breakdown of its electronic and mechanical parts. --- ### 1. General Specifications This part is used to split a single 100GbE port into four 25GbE ports. | Feature | Specification | | :--- | :--- | | **Connector A** | QSFP28 (SFF-8665) | | **Connector B** | 4x SFP28 (SFF-8402) | | **Data Rate** | 100Gbps (4x 25Gbps) | | **Cable Type** | Passive Direct Attach Copper (DAC) | | **Wire Gauge** | Typically 26AWG to 30AWG (depending on length) | | **Impedance** | 100 Ohms | --- ### 2. Electronic Components & Internal Design #### A. EEPROM (I2C Interface) Inside each connector head (both the QSFP28 and the four SFP28 ends), there is a small **EEPROM chip**. * **Function:** It stores "Vital Product Data" (VPD) such as the manufacturer name, part number, serial number, and supported protocols. * **Protocol:** Communicates via the **I2C serial interface** with the switch or network interface card (NIC). This allows the hardware to identify the cable and apply the correct signal settings. #### B. The Copper Media (Twinax) Unlike standard Ethernet cables, this uses **Twinaxial cabling**: * **Conductors:** Two inner conductors per signal pair, wrapped in a foil shield and an outer braid. * **Signaling:** Uses Differential Signaling to reduce EMI (Electromagnetic Interference) and crosstalk. * **Passive Nature:** The "R2/N" designation usually implies a **passive** design, meaning there are no signal amplifiers or re-timers inside. The signal integrity relies entirely on the quality of the copper and the host device's EDC (Electronic Dispersion Compensation). #### C. PCB Termination Each connector contains a small **Internal Printed Circuit Board (PCB)**: * **Gold Fingers:** The contact points that slide into the cage are gold-plated for high conductivity and corrosion resistance. * **AC Coupling Capacitors:** These are surface-mounted on the internal PCB to block DC voltage while allowing high-speed AC data signals to pass through. --- ### 3. Mechanical & Structural Parts * **Zinc Die-Cast Housing:** The connector shells are made of zinc alloy to provide superior EMI shielding and physical durability. * **Pull-to-Release Latch:** A plastic or rubberized tab (often colored for identification) used to retract the locking mechanism from the port cage. * **Strain Relief:** Molded plastic at the junction where the cable meets the connector to prevent internal wiring breakage from bending. --- ### 4. Application Context The "4133" series is commonly used in high-density data centers to connect a **100G Switch** (Top of Rack) to **four 25G Servers**.